Overlapping syndrome with concomitant mGluR2-Ab and GFAP-Ab: A case report

Area of Science:

• Neuroimmunology
• Autoimmune Neurology
• Pediatric Neurology

Background:

• Autoimmune encephalitis and myelitis are increasingly recognized neurological disorders.
• Antibodies targeting neuronal and glial antigens are key diagnostic and pathogenic markers.
• Metabotropic glutamate receptor 2 (mGluR2) and glial fibrillary acidic protein (GFAP) are implicated in distinct autoimmune syndromes.

Purpose of the Study:

• To report the first case of concurrent anti-mGluR2 and anti-GFAP antibodies in a pediatric patient.
• To describe the clinical presentation, diagnostic challenges, and treatment outcomes of this overlapping autoimmune syndrome.
• To highlight the potential co-pathogenic role of mGluR2-Ab and GFAP-Ab in neurological deterioration.

Main Methods:

• Case report of an 11-year-old male with acute neurological deterioration.
• Serological testing for antibodies against mGluR2 and GFAP.
• Neuropathological examinations were conducted.
• Treatment involved combination immunotherapy: intravenous methylprednisolone, human immunoglobulin, and plasma exchange.

Main Results:

• The patient presented with meningitis, encephalitis, and myelitis.
• Initial testing revealed mGluR2-Ab; subsequent testing confirmed coexisting GFAP-Ab.
• Pathogenic examinations were negative.
• Following immunotherapy, the patient showed a favorable prognosis with residual neurogenic bladder.

Conclusions:

• This case represents the first documented instance of overlapping autoimmune syndrome with concurrent mGluR2-Ab and GFAP-Ab.
• The coexistence of these antibodies can manifest as simultaneous meningoencephalomyelitis and ataxia, complicating diagnosis and treatment.
• Timely combined immunotherapy is crucial, and mGluR2-Ab and GFAP-Ab may act as jointly responsible antibodies in such complex autoimmune neurological conditions.